Poster: Crane Safety
Poster: Crane Safety (Spanish)
Crane Safety Guide (Spanish)
Cranes are used on nearly all construction projects at one time or another. From a basic boom truck used to deliver materials, to a large hammerhead tower crane or a mobile hydraulic crane, this equipment can be observed on almost all construction jobsites. Fortunately, accidents involving cranes, especially severe ones, are not typical. However, crane accidents, when they do occur, tend to be severe.
Crane accidents fall into four basic categories:
1. Tipping can occur when the operator handles a load that exceeds the stability rating of the equipment for a given weight and radius.
2. Structural failure can occur when a hoisted load exceeds the crane’s structural limitations.
3. Rigging failure can occur when the object being lifted (picked) is not properly rigged or corrected to the load block or headache ball.
4. Electrocution can occur when the operator maneuvers the load, line or boom too close, or makes contact with an energy source (typically an overhead power line).
If the crane standards are strictly followed, most crane accidents are preventable.
Electrocution hazards are addressed by OSHA in 1926.1408.
In the event that any part of the crane (load line or load including rigging and lifting accessories), if operated up to the equipment’s maximum working radius in the work zone, could get any closer than 20 feet to a power line, OSHA provides the employer with three options to avoid accidental contact:
Option 1 – De-energize and ground. Confirm from the utility owner/operator that the power line has been de-energized and visibly grounded at the jobsite.
Option 2 – 20-foot clearance. Ensure that no part of the equipment (load line or load including rigging and lifting accessories) gets any closer than 20 feet to the power line by implementing measures specified by OSHA in 1926.408(b).
Option 3 – Use clearances identified in Table A.
TABLE A—MINIMUM CLEARANCE DISTANCES
| Voltage (nominal, kV, alternating current) |
Minimum clearance distance (in feet) |
|---|---|
| Up to 50 | 10 |
| Over 50 to 200 | 15 |
| Over 200 to 350 | 20 |
| Over 350 to 500 | 25 |
| Over 500 to 750 | 35 |
| Over 750 to 1,000 | 45 |
| Over 1,000 | (As established by the utility owner/operator or registered professional engineer who is a qualified person with respect to electrical power transmission and distribution.) |
| Note: The value that follows "to" is up to and includes that value. For example, over 50 to 200 means up to and including 200kV. | |
Also see 1926.1409 or1926.1411, whichever is appropriate, and 1926.1417(u).
Tipping (Stability)
Stability and structural failure can result when there is too much weight applied for a given load radius. To avoid this hazard, the crane operator must be capable of making sure that a crane is operated within its design limitations. The only safe and effective way to make sure that the crane is operated within its design limitations, the crane operator must be capable of reading, comprehending, and applying the load capacity charts provided by the manufacturer.
Another critical point with crane operation is stability. The calculations used to determine the capacities in the load chart are based on the crane being within one percent of level. If the crane is not within one percent of level, the load chart will not be correct, and the crane must not be operated. It is imperative that cranes be properly set on level, stable ground.
Stability and ground support for cranes are discussed in the OSHA standard at 1926.1402(a) through (f). Most manufacturers' manuals state that the outrigger supports supplied with cranes may not be of sufficient size to support the crane under all soil conditions. Therefore, the crane operator must determine the soil conditions and provide additional cribbing under the outrigger pads to provide the necessary support.
Other aspects of crane operation can lead to accidents and injuries. Accidents and injuries can result from the load being lifted or from the rotating superstructure. OSHA addresses crane swing radius requirements in OSHA 1926.1424(a) through (a)(3)(ii), which include requirements to prevent employees from being struck or crushed by the crane superstructure. Keep employees clear of loads about to be lifted and do not allow employees to work or stand under suspended loads. Tag lines should be used to control suspended loads.
Improper signaling can cause an operator to swing a load into employees or lower the load prematurely. Hand signals to crane operators should be those prescribed by the ANSI standard. Radios can also be an effective method for signal persons to communicate with crane operators. Signal persons must be qualified to perform their duties as required by OSHA 1926.1419 and 1926.1428.
Operators may also rely on the load moment indicator (LMI) or computer to warn them when they are nearing the crane’s capacity. Many crane accidents have resulted because the LMI was not properly set to the configuration of the crane, giving the operator a false sense of security. Had the LMI been properly programmed in most of these situations, the operator would have received an overload warning.
High winds can also cause crane accidents due to overloading. Wind stress has the potential for adding additional stress to the boom and can also move the load outside the present load radius causing a structural or stability failure. The manufacturer’s crane specifications usually stipulate maximum wind velocities for safe operation. An effective method for monitoring and determining wind speed should be provided at the jobsite.
Standard Requirements
The OSHA standard requires that cranes be inspected by a competent person prior to each shift and must be completed before or during the shift (1926.1412[d]), each month the equipment is in service (1926.1412[e]), and at least every 12 months by a qualified person (1926.1412[f]). Documentation of monthly inspections must be maintained by the employer that conducts the inspection (1926.1412[e][3]). The annual/comprehensive inspection must be documented, maintained, and retained for a minimum of 12 months by the employer who conducts the inspection. (1926.1412[f][7]).
The OSHA standard requires that rigging equipment be inspected by a competent person. The visual inspections must be initiated prior to each shift the equipment is used and must be completed before or during the shift: (1926.1413[a]); monthly (1926.1413[b]); and every 12 months (1926.1413[c][1]). The annual comprehensive inspection must be documented (1926.1413[c][4]).
OSHA incorporates the ANSI B-30.5-2004 Standard for Mobile Cranes by reference. This standard addresses operator qualifications, as well as design, use, and inspection criteria. All owners and operators of mobile cranes should have and understand the additional requirements of this ANSI standard.
Effective November 10, 2014, OSHA now requires crane operators to be certified (1926.1427). On September 25, 2014, federal OSHA extended the deadline for crane operator certification to November 10, 2017.
The OSHA Crane Rule became effective in Utah on August 8. 2011. The provisions of 29 CFR 1926.1427 related to operator certification became effective in Utah on November 10, 2014 and applies to the entire construction industry and any type of construction work, without exception.
The crane operator manual supplied by the crane manufacturer is essentially incorporated by reference. OSHA 1926.1417(a) stipulates that the employer must comply with all manufacturer procedures applicable to the operational functions of equipment, including its use with attachments.
Crane accidents are preventable if the crane is properly set up, properly inspected and maintained, operated within the operational limitations established by the manufacturer; and the load safely rigged.
Always use safe rigging practices. OSHA 1926.1404(r)(1) requires that riggers be qualified. Note that OSHA also stipulates that certified crane operators do not necessarily meet the requirements of a qualified rigger. However, a certified operator may meet the requirements of a qualified rigger depending on the operator’s knowledge and experience with rigging.
The latch in the hook throat opening should never be tied back or tied in the open position. Never suspend employees form a crane (riding the ball) and only use a crane to suspend a personnel platform as a last resort.
Remember that the key to crane safety depends on the experience and ability of the operator and their understanding of the equipment and its limitations and their understanding of load charts.
Resources
OSHA 1926.550
OSHA 1926.251
osha.gov
ANSI
Additional Resources
WCF Insurance Safety Department
(385) 351-8103
NOTICE: This guide may make reference to the Occupational Safety and Health Administration (OSHA) regulations; however the guide is not legal advice as to compliance with OSHA or other safety laws, codes, or regulations. Compliance with OSHA and other safety laws codes or regulations, and maintaining a safe work environment for your employees remains your responsibility. WCF Insurance does not undertake to perform the duty of any person to provide for the health or safety of your employees. WCF Insurance does not warrant that your workplace is safe or healthful, or that it complies with any laws, regulations, codes, or standards.